Help with going back to stock rooted rom with bootstrap

Hey everybody, so I rooted my Bionic and made a backup of the root using bootstrap, and installed the blurred rom, a custom boot for when i turn on the phone, and the webtop hack and Titanium Backup, now when I go to bootstrap recovery to try and flash the backed up stock root and click on restore and the file it says MD5 mismatch and stops. What can I do? Im a noob too so if you can please explain in easy terms.
Also I made sure all the apps I had frozen were unfrozen and everything.
I tried reading other posts but couldn't find anything I understood completely. Do I have to go to bootstrap and wipe/ factory reset and wipe cache before restoring?
thanks

Hey everybody, so I rooted my Bionic and made a backup of the root using bootstrap, and installed the blurred rom, a custom boot for when i turn on the phone, and the webtop hack and Titanium Backup, now when I go to bootstrap recovery to try and flash the backed up stock root and click on restore and the file it says MD5 mismatch and stops. What can I do? Im a noob too so if you can please explain in easy terms.
Also I made sure all the apps I had frozen were unfrozen and everything.
I tried reading other posts but couldn't find anything I understood completely. Do I have to go to bootstrap and wipe/ factory reset and wipe cache before restoring?
thanks